Anti‐PD‐L1 antibody TQB2450 combined with tyrosine kinase receptor inhibitor AL2846 for immunotherapy‐refractory advanced hepatocellular carcinoma and esophageal squamous cell carcinoma: A prospective phase 1b cohort study

Abstract Background Effective systemic therapy remains limited for advanced esophageal squamous cell carcinoma (ESCC) and hepatocellular carcinoma (HCC), particularly after prior failed treatment with immune checkpoint inhibitors (ICIs). Theoretically, a combination of tyrosine kinase inhibitors (TKIs) with ICIs may restore immunotherapy sensitivity. Methods In this phase 1b study, patients received AL2846, an antiangiogenic TKI with multiple targets (c‐MET, VEGFR1, c‐KIT, Axl, RET, KDR, and VEGFR3), in combination with an anti–PD‐L1 antibody (TQB2450) until disease progression, intolerable toxicity, death, or discontinuation for any cause. The primary end points included overall response rate (ORR) and safety, with secondary end points encompassing progression‐free survival (PFS), overall survival (OS), disease control rate (DCR), and duration of response. Results Between November 2021 and September 2022, 18 patients with ESCC and 15 patients with HCC, whose ORR was 11.1% (95% confidence interval CI, 3.1%–32.8%) and 0%, respectively, were enrolled. Adverse events (AEs) of any grade and treatment‐related AEs were documented in 32 patients (97.0%) and 31 patients (93.9%), respectively. Grade 3 or higher AEs were observed in 10 patients (30.3%), with vomiting (6.1%) and infectious pneumonia (9.1%) being the most prevalent. Median PFS and OS values were 3.22 months (95% CI, 1.35–5.68 months) and 5.98 months (95% CI, 3.71–8.87 months), respectively, in patients with ESCC, and 5.55 months (95% CI, 2.66 months to not evaluable NE) and 16.72 months (95% CI, 4.86 months to NE), respectively, in patients with HCC. The DCRs were 66.7% (95% CI, 43.75%–83.72%) in patients with ESCC and 73.3% (95% CI, 48.05%–89.10%) in patients with HCC. Conclusions Combined TQB2450 and AL2846 therapy exhibited a favorable safety profile in immunotherapy‐refractory patients with advanced ESCC and HCC.